Device to establish an electrical circuit



Jan. 29, 1957 N. A. WALKER 2,779,842

DEVICE TO ESTABLISH AN ELECTRICAL CIRCUIT Filed April 12, 1955 W Cm? a detached therefrom,

United States Patent This invention relates to a device for attachment to electrical Wires to establish an electrical circuit.

One object of my invention is to provide a device, responsive to heat, having two separate parts, each of which can make a contact with a wire, and one of which can be wrapped, at least partly, around the other.

Another object is to provide such a device with conductors that can be used to make contact with wires that extend at right angles to each other, to thereby establish an electrical circuit.

A further object is to provide a device of such simple construction that its cost is relatively low, and the two parts of which can instantly be attached to two wires, or

by an unskilled person.

The foregoing and other objects, which will appear as the nature of the invention is better understood, may be accomplished by a construction, combination and arrangement of parts such as is disclosed by the drawing. The nature of the invention is such as to render it susceptible to various changes and modifications, and, therefore, I am not to be limited to the construction disclosed by the drawing nor to the particular parts described in the specification; but am entitled to all such changes therefrom as fall within the scope of my claims.

in the drawings:

Fig. 1 is a side elevational view of my device connected to two wires in position of use.

Fig. 2 is an end elevational view of the assembly shown in Fig. 1.

Fig. 3 is a perspective view of the inner conductor of "my device.

Fig. 4 IS a perspective view of the outer conductor of my device.

Fig. 5 is' an enlarged, sectional view taken on the 'line 5-5 of Fig. 1.

Fig. 6 is a side elevational view of a modified form of I :an inner conductor connected to two wires extending at ri ht angles to each other.

Pig. 7 is a side elevational view of a modified form of "an outer conductor device which connects with wires similar to Fig. 7.

Fig. 8 is a diagrammatic view of both forms of my device inposition of use, connected to an electrical, .signaling system.

of use, is an open tubular shape. It is covered with insulation 13 and at the inner surface two uncovered, electricity conducting prongs 20 extend laterally outward therefrom. The number of prongs 20 may be varied from one to several. When placed in position the prongs 7 .20 extend through said insulation 14 and penetrate partly into said wire 10, formed of the usual strands, to thereby make electrical connection therewith.

My device also has a thermostatically controlled, outer conductor 22 similar to conductor 16; but larger, being capable of extending from outside said wire 12 to and outside a portion of said inner conductor 16. It is covered with insulation 24, and at the inner surface two uncovered, electricity conducting prongs 26 extend laterally outward therefrom through the insulation 14 of, and penetrate partlyinto, the other said wire 12, as above described with regard to the inner conductor 16.

The said insulation coverings 18 and 24 are made of amaterial such as a plastic having a relatively low melting point, as 140 degrees F., for instance, so that it will melt, soften, or the insulation otherwise breaks down,.to thus expose the metal bodies, in case of fire which causes a rise in temperature to said melting point.

The outer conductor 22 has a greater girth than, and extends partly around the inner conductor 16, being in firm contact therewith where it overlies the latter, as illustrated in Fig. 5. Whenthe insulation coverings 18 and 24 melt and uncover the metal bodies of said two conductors an electrical circuit is established which extends across the two wires 10 and 12, being made possible by'this contact of the metal in each of the two conductors aforesaid. The circuit thus established can serve to ring a bell, sound a buzzer, or otherwise provide a signal.

in Figs. 6 and 7 of the drawing, 1 show a modified form of inner and outer conductors 23 and 34 respectively, which are of general T-shape and are suitable to use where a pair of wires 25 and 27 extend at an angle to, such as a right angle, and are separate from the pair of wires 16 and 3.2. They may he covered with insulation as described above. Said inner conductor 28 has two laterally extending, electricity conducting prongs 30 at tr e cross-piece of the T-shape and one such prong 32 at the part thereof. Said two prongs are located laterally beyond said leg part at opposite sides.

There is an outer and larger conductor 34 which has two electricity conducting prongs 38 extending laterally from the cross-piece of the T-shape. It also has one such prong 40 extending laterally from the leg part there of. Said two prongs 33 are located laterally beyond said latter leg part at opposite sides.

When the metal bodies of these inner and outer condoctors 28 and 34 respectively are in contact with each other, with the outer conductor at the outside, electrical current passing through said wires 10 and 12 also will pass through said wires 26 and 27, thus providing a circult through the latter two wires as well as through said wires 10 and 12.

in 8 I show both forms of my device connected to an electrical signal system in which the source of current is a battery from which said wire 12 extends to the said conductor 22 in the form of my device shown in Figs. 1 to 5, and from there it extends to the conductor 34 in the form of device shown in Figs. 6 and 7, and thence to a contact member of a testing switch S. The other said wire 10 extends from a contact member of said testing switch S to said conductor 33, thence to the said conductor l5 and thence to a signal bell A or other form of the insulation on said conductors 16 and 22 melts and runs an electrical circuit will be established through them from said battery B to said signal bell A to thereby actuate the latter.

Conductors 16 and 22 are also shown on said wires 25 and so that, if, at that point, it becomes sufliciently hot to melt the insulation on the latter said wires, the signal bell will be actuated. In such an arrangement said conductors 28 and are not covered with insulation, hence connection between wires 10 and 12 in one circuit, and wires 25 and 27 in the other, is already established.

leg

trical circuit comprising a T-shaped inner conductor embodying an electricity conducting body forming the cross- -piece and leg of the said T and a plurality of electricity conducting prongs one of which extends laterally outward from said leg and one of which extends laterally outward from said cross-piece and at opposite sides of said leg, and a T-shaped. outer conductor embodying an electricity conducting body forming the cross-piece and leg of the said T and a plurality of electricity conducting prongs one of which extends laterally outward from said latter leg and one of which extends laterally outward from said latter cross-piece and at opposite sides of said latter leg, said outer conductor leg and cross-piecebeing adapted to extend outside of and overlie part of said leg and part of said cross-piece respectively of said inner conductor.

2. A device for attachment to wires to establish an electrical circuit comprising a T-shaped inner conductor embodying an electricity conducting body forming the cross-piece and leg of the said T and a plurality of electricity conducting prongs one of which extends laterally outward from said leg and two of which extend laterally outward from said cross-piece and at opposite sides of said leg and a T-shaped, outer conductor embodying an electricity conducting body forming the cross-piece and leg of the said T and a plurality of electricity conducting prongs one of which extends laterally outward from said latter leg and two of which extend laterally outward from said latter cross-piece and at opposite sides of said latter leg, said outer conductor being larger than said inner conductor the leg and cross-piece being adapted to extend outside of and overlie part of said leg and part of said cross-piece respectively of said inner conductor, and insulation on both of said bodies adapted to melt at a predetermined temperature.

3. A device for attachment to Wires in combination with two pairs of electricity conducting wires, one pair of which extends at an angle to the other pair, said device comprising a T-shaped inner conductor embodying an electricity conducting body forming the cross-piece and leg of said T and a plurality of electricity conducting prongs one of which extends laterally outward from said leg and penetrating one of a first said pair of wires, and one of which prongs extends laterally outward from said cross-piece and penetrating one of a second said pair of wires, and a T-shaped, outer conductor embodying an v electricity conducting body forming the cross-piece and leg of said latter T and a plurality of electricity conducting prongs one of which extends laterally outward from said latter leg and penetrating the other wire of the first said pair of wires and one of which prongs extends laterally outward from said latter cross-piece the other of said second said pair of wires, said outer conductor crosspiece and leg extending from outside said other wire to and outside of and in contact with said cross-piece and leg of said inner conductor.

4. A device for attachment to wires in combination with two pairs of electricity conducting wires, one pair of which extends at an angle to the other pair, said device comprising a T-shaped inner conductor embodying an electricity conducting body forming the cross-piece and leg of said T and three electricity conducting prongs one of which extends laterally outward from said leg and penetrating one of a first said pair of wires, and two of which prongs extend laterally outward from said crosspiece and at opposite sides of said leg and penetrating one of a second said pair of wires, and a T-shaped, outer conductor embodying an electricity conducting body forming the cross-piece and leg of said latter T and three electricity conducting prongs one of which extends laterally outward from said latter leg and penetrating the other of first said pair of wires and two of which prongs extend laterally outward from said latter cross-piece and at opposite sides of said latter leg and penetrating the other of said second said pair of wires, said outer conductor crosspiece and leg extending from outside said other wire to and outside of and in contact with said cross-piece and leg of said inner conductor.

5. A device for attachment to wires in combination with two pairs of electricity conducting wires, one pair of which extends at an angle to the other pair, said device comprising a T-shaped inner conductor embodying an electricity conducting body forming the cross-piece and leg of said T and three electricity conducting prongs one of which extends laterally outward from said leg and penetrating one of a first said pair of wires, and two of which prongs extend laterally outward from said crosspiece at opposite sides of said leg, and penetrating one of a second said pair of wires and at points spaced apart and in opposite lateral directions from said first-mentioned prong, and a T-shaped, outer conductor embodying an electricity conducting body forming the cross-piece and leg of said latter T and three electricity conducting prongs one of which extends laterally outward from said latter leg and penetrating the other of the first said pair of wires and two of which prongs extend laterally outward from ductor cross-piece and leg extending from outside said other wire to and outside of and in contact with said cross-piece and leg of said inner conductor, and insulation on both of said bodies adapted to melt at a predetermined temperature.

6. A device for attachment to wires to establish an electrical circuit comprising an open-mouthed, inner conductor embodying an electricity conducting body and an electricity conducting prong extending laterally outward therefrom, and an open-mouthed, outer conductor embodying an electricity conducting body and an electricity conducting prong extending laterally outward therefrom, said outer conductor being of greater girth than, and adapted to extend outside of and contact and overlie, part only of said inner conductor, and insulation on said bodies adapted to melt at a predetermined temperature.

References Cited in the file of this patent UNITED STATES PATENTS 1,139,486 Caldwell May 18, 1915 2,110,513 Toelke Mar. 8, 1938 2,186,112 Keen Jan. 9, 1940 2,204,237 Slack et a1. June 11, 1940 

